1. Field of the Invention
The present invention relates to a filter for a display device, and more particularly, to a filter for a display device which can reduce its manufacturing costs while maintaining its capability of blocking electromagnetic waves.
2. Description of the Related Art
As information is getting more important in the modern society, remarkably advanced image display devices and their parts are being distributed. The display devices include display devices for TVs, monitors of personal computers (PCs) and so on, and their distribution is greatly increasing. Further, the display devices are getting larger in a screen size and thinner at the same time.
In general, a plasma display panel (PDP) device is in the limelight as a next generation display device since it can be made larger in a screen size and thinner at the same time than a cathode ray tube (CRT), which is representative of existing display devices. The PDP device displays an image using a gas discharge phenomenon and has an excellent display performance in relation to a luminance, a contrast ratio, an image retention, a viewing angle, or the like. Further, the PDP device is in the spotlight as a display device which can replace the CRT device because the PDP device can be easily made larger in a screen size than other display devices and as a thinner image display device, the PDP device has the most suitable characteristics for future high quality digital televisions.
The PDP device applies a direct or alternating voltage to the electrodes to cause gas discharge and then ultraviolet radiation. The ultraviolet activates a fluorescent layer to generate light. However, the PDP device has drawbacks that electromagnetic interference (EMI), near infrared rays (NIR), and neon light of orange color are generated. The EMI is harmful to the human body, the NIR causes malfunction of precision appliances such as a remote controller, and the neon light deteriorates color purity.
Therefore, the PDP device employs a PDP filter in order to block electromagnetic waves and near infrared rays, reduce light reflection, and improve color purity.
The PDP filter of the related art includes a transparent substrate and functional layers such as an electromagnetic shielding layer, a neon light shielding layer, a near-infrared shielding layer and an anti-reflection layer, which are laminated on the transparent substrate.
The electromagnetic shielding layer is earthed to a case or the like of a display device so as to allow electromagnetic waves generated from a display panel to be discharged to the ground such as the case before reaching display viewers.
However, such a PDP filter of the related art has a problem that manufacturing cost is high because a grounding path of electromagnetic waves between the electromagnetic shielding layer and the ground such as the case is inefficient.